Fast foup swapping with a foup handler

ABSTRACT

A vertical batch furnace assembly for processing wafers having a cassette handling space, a wafer handling space, and a first wall and separating the cassette handling space from the wafer handling space. The first wall has at least one wafer transfer opening in front of which, at a side of the first wall which is directed to the cassette handling space, a wafer transfer position for a wafer cassette is provided. The cassette handling space comprises a cassette storage having a plurality of cassette storage positions and a cassette handler configured to transfer wafer cassettes between the cassette storage positions and the wafer transfer position. The cassette handler has a first cassette handler arm and a second cassette handler arm.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority to U.S. Provisional Patent ApplicationSer. No. 63/018,810 filed May 1, 2020 titled FAST FOUP SWAPPING WITH AFOUP HANDLER, the disclosure of which is hereby incorporated byreference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to a vertical batch furnaceassembly comprising a cassette handler.

BACKGROUND

Vertical batch furnace assemblies for processing wafers comprise acassette handling space, a wafer handling space, and a wall separatingthese two spaces. The wall has a wafer transfer opening provided with acassette door opener device in front of which a wafer transfer positionfor a wafer cassette is provided. The cassette handling space isprovided with cassette handler which may transport wafer cassettesbetween the wafer transfer position and a cassette storage in which thewafer cassettes may be stored. The wafer handling space of the verticalbatch furnace assembly may also be provided with a wafer handler whichmay remove wafers from a wafer cassette which is in the wafer transferposition, and transfer those wafers through the wafer transfer openingto a wafer boat for applying a treatment in a process chamber. Aftertreatment of said wafers the wafer handler may also put the wafers backinto the wafer cassette which is in the wafer transfer position.Subsequently, the cassette handler may transfer the wafer cassette tothe cassette storage and replace it with another wafer cassette from thecassette storage.

SUMMARY

This summary is provided to introduce a selection of concepts in asimplified form. These concepts are described in further detail in thedetailed description of example embodiments of the disclosure below.This summary is not intended to identify key features or essentialfeatures of the claimed subject matter, nor is it intended to be used tolimit the scope of the claimed subject matter.

It may be realized that typically multiple wafer cassettes need to beunloaded to fill an entire wafer boat and that during the transfer ofwafer cassettes to and from the wafer transfer position, the waferhandler may be unable to transfer wafers and remains idle. Also, duringtransfer by the wafer handler of wafers to and/from the cassette whichis in the wafer transfer position, the cassette hander may be unable totransport a wafer cassette to or from the wafer transfer position andremains idle. These idle times may be detrimental to the efficiency ofthe vertical batch furnace assembly.

Therefore, it may be an object to provide a vertical batch furnaceassembly with improved capacity.

To that end, there may be provided a vertical batch furnace assemblyaccording to claim 1. More particularly, there may be provided avertical batch furnace assembly for processing wafers. The verticalbatch furnace assembly may comprise a cassette handling space, a waferhandling space, and a first wall separating the cassette handling spacefrom the wafer handling space. The first wall may have at least onewafer transfer opening in front of which, at a side of the first wallwhich is directed to the cassette handling space, a wafer transferposition for a wafer cassette is provided. The cassette handling spacemay comprise a cassette storage and a cassette handler. The cassettestorage may have a plurality of cassette storage positions eachconfigured to store a wafer cassette provided with a plurality ofwafers. The cassette handler may be configured to transfer wafercassettes between the cassette storage positions and the wafer transferposition. The cassette handler may comprise a first cassette handlerarm, and a second cassette handler arm.

For purposes of summarizing the invention and the advantages achievedover the prior art, certain objects and advantages of the invention havebeen described herein above. Of course, it is to be understood that notnecessarily all such objects or advantages may be achieved in accordancewith any particular embodiment of the invention. Thus, for example,those skilled in the art will recognize that the invention may beembodied or carried out in a manner that achieves or optimizes oneadvantage or group of advantages as taught or suggested herein withoutnecessarily achieving other objects or advantages as may be taught orsuggested herein.

Various embodiments are claimed in the dependent claims, which will befurther elucidated with reference to examples shown in the figures. Theembodiments may be combined or may be applied separate from each other.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments will becomereadily apparent to those skilled in the art from the following detaileddescription of certain embodiments having reference to the attachedfigures, the invention not being limited to any particular embodiment(s)disclosed.

BRIEF DESCRIPTION OF THE FIGURES

While the specification concludes with claims particularly pointing outand distinctly claiming what are regarded as embodiments of theinvention, the advantages of embodiments of the disclosure may be morereadily ascertained from the description of certain examples of theembodiments of the disclosure when read in conjunction with theaccompanying drawings, in which:

FIG. 1 shows an example of the relevant part of the vertical batchfurnace assembly according to the description;

FIG. 2 shows an example of a cassette handler arm according to thedescription;

FIG. 3 shows the example of FIG. 1 wherein the cassette handler armshave transferred the cassettes;

FIG. 4 schematically shows another example of the vertical batch furnaceassembly according to the description.

DETAILED DESCRIPTION OF THE FIGURES

In this application similar or corresponding features are denoted bysimilar or corresponding reference signs. The description of the variousembodiments is not limited to the example shown in the figures and thereference numbers used in the detailed description and the claims arenot intended to limit the description of the embodiments, but areincluded to elucidate the embodiments.

Although certain embodiments and examples are disclosed below, it willbe understood by those in the art that the invention extends beyond thespecifically disclosed embodiments and/or uses of the invention andobvious modifications and equivalents thereof. Thus, it is intended thatthe scope of the invention disclosed should not be limited by theparticular disclosed embodiments described below. The illustrationspresented herein are not meant to be actual views of any particularmaterial, structure, or device, but are merely idealized representationsthat are used to describe embodiments of the disclosure.

As used herein, the term “wafer” may refer to any underlying material ormaterials that may be used, or upon which, a device, a circuit, or afilm may be formed.

In the most general term the present disclosure may provide a verticalbatch furnace assembly 10 for processing wafers. An example of therelevant part of the vertical batch furnace assembly 10 is shown inFIGS. 1, 3 and 4 to which reference is made in the following but whichare non-limiting examples. The vertical batch furnace assembly 10 maycomprise a cassette handling space 12, a wafer handling space 14, and afirst wall 16 separating the cassette handling space 12 from the waferhandling space 14. The first wall 16 may have at least one wafertransfer opening 20 in front of which, at a side of the first wall 16which is directed to the cassette handling space 12, a wafer transferposition 22 for a wafer cassette 60 is provided. The cassette handlingspace 12 may comprise a cassette storage and a cassette handler 26, 28,30. The cassette storage may have a plurality of cassette storagepositions 24 each configured to store a wafer cassette 60 provided witha plurality of wafers. The cassette handler 26, 28, 30 may be configuredto transfer wafer cassettes 60 between the cassette storage positions 24and the wafer transfer position 22. The cassette handler 26, 28, 30 maycomprise a first cassette handler arm 28, and a second cassette handlerarm 30. In an embodiment, the cassette handler 26, 28, 30 may furthercomprise an elevator mechanism configured to reach wafer cassettesplaced on cassette storage positions at different vertical levels withinthe cassette handling space.

When a first wafer cassette 60 is in the wafer transfer position 22, awafer handler (not shown) may load/unload wafers in/from the first wafercassette 60, e.g. to transfer the wafers to a wafer boat in which thewafers may be mounted during a treatment in a process chamber of thevertical batch furnace. With the vertical batch furnace assembly 10according the description comprising the cassette handler 26, 28, 30having a first and a second cassette handler arm 28, 30, the cassettehandler 26, 28, 30 may already get a second wafer cassette 60 from thecassette storage and transfer it to location near the wafer transferposition 22, while the wafer handler is loading/unloading the wafersfrom the first wafer cassette 60. The cassette handler 26, 28, 30 mayuse one of the first and second cassette handler arms 28, 30 to hold thesecond wafer cassette 60, while the other one of the cassette handlerarm 28, 30 is free. As soon as the wafer handler is ready with theloading/unloading of the first wafer cassette 60, the cassette handler26, 28, 30 may remove the first wafer cassette 60 from the wafertransfer position 22 with the free cassette handler arm 28, 30, andimmediately afterwards place the second wafer cassette 60 in the wafertransfer position 22 with the other cassette handler arm 28, 30. Thecassette handler 26, 28, 30 does not have to transfer the first wafercassette 60 all the way to a cassette storage position 24 and transferthe second wafer cassette 60 all the way from another cassette storageposition 24 to the wafer transfer position 22, thus reducing thetransfer path and thereby saving time in which the wafer handler wouldotherwise remain idle.

In an embodiment the cassette handler 26, 28, 30 may further comprise amovable carriage 26 which is movable in a first direction 32. Both thefirst cassette handler arm 28 and the second cassette handler arm 30 mayeach with a respective first end be connected to the movable carriage26.

Due to the fact that a single carriage 26 may carry both cassettehandler arms 28, 30, only a single drive may be needed to transport botharms along the first direction.

In an embodiment, the first cassette handler arm 28 and the secondcassette handler arm 30 may each have a respective second end, whereineach respective arm 28, 30 may be configured to move its second end awayfrom and towards its first end.

Such an embodiment enable the cassette handler arms 28, 30 to reachextend and retract.

In a further elaboration, both the first and second cassette handlerarms 28, 30 at or near a first end thereof may be pivotably connected tothe movable carriage 26 of the cassette handler 26, 28, 30. Therespective cassette handler arm 28, 30 at or near the second end thereofmay comprise a cassette gripper 34 configured to grip a wafer cassette60. The cassette gripper 34 of the first cassette handler arm 28 may bepivotably connected to the first cassette handler arm 28. The cassettegripper 34 of the second cassette handler arm 30 may be pivotablyconnected to the second cassette handler arm 30.

The movable carriage 26 provides a base for movement of the two cassettehandler arms 28, 30 simultaneously. When attached to the movablecarriage 26, both arms 28, 30 may move together with the movablecarriage 26. In this way both arms may be near the wafer transferposition 22 or both may be near a cassette storage position 24.

In an embodiment, the first direction may be substantially vertical andthe cassette handler 26, 28, 30 may further comprise an elevatormechanism which may be configured to transfer the movable carriage 26upwardly and downwardly so that the first and second cassette handlerarms 28, 30 are able reach wafer cassettes placed on cassette storageposition at different vertical levels within the cassette handlingspace.

In such this embodiment, movement in a plane perpendicular to the firstdirection 32 may be done by the cassette handler arms 28, 30 themselveswhich may, for example, be pivotably connected to the movable carriage26. Alternatively, a guide 36 on which the movable carriage 26 may bemounted for movement along the first direction may be rotatable aroundan axis extending in the first direction. It is also possible that themovable carriage 26 is rotatable around a guide 36 along an axisextending in the first direction. That same guide 36 may also serve asthe guide 36 for movement of the movable carriage 26 along the firstdirection.

In an embodiment, the elevator mechanism 36, 38, 40 may comprise atleast one first direction guide 36, 38 extending in the first direction32. The movable carriage 26 may be moveably mounted on the at least onefirst direction guide 36, 38 and may be moveable along the firstdirection 32. The at least one first direction guide 36, 38 thusprovides the movement of the movable carriage 26 in the first direction32.

In an embodiment, of which an example is shown in FIGS. 1 and 3, themovable carriage 26 may be additionally movable in a second direction42, perpendicular to the first direction 32. To that end, the elevatormechanism 36, 38, 40 may comprise at least one first direction guide 36,38 extending in the first direction 32 and a transverse guide 40extending in the second direction 42. The movable carriage 26 may bemoveably mounted on the transverse guide 40 and may be moveable alongthe second direction 42. Transverse guide 40 may be movably mounted onthe at least one first direction guide 36, 38 and may be moveable alongthe first direction 32. The at least one first direction guide 36, 38may comprise a first guide 36 and a second guide 38. The transverseguide 40 may be mounted between said first guide 36 and said secondguide 38. The at least one first direction guide 36, 38, and thetransverse guide 40 thus together provide the movement along the firstdirection 32 and along the second direction 42. Such a configuration isextremely stable and the carriage 26 may be moved at relatively highspeed in a plane of movement which is parallel to the first and seconddirections.

In an embodiment, in which the carriage 26 is only moveable along thefirst direction, of which an example is shown in FIG. 4, the cassettestorage positions 24 may be located at equal distances from a line ofmovement 62 along which the movable carriage 26 is moveable in the firstdirection. The wafer transfer position 22 may be positioned atsubstantially the same distance from the line of movement 62 as thecassette storage positions 24. In such a configuration, the cassettestorage positions 24 may be positioned in circles or circle segmentsaround the line of movement 62 at different vertical levels.

In another embodiment, in which the carriage 26 is moveable along thefirst direction and the second direction which are perpendicular to eachother, of which examples are shown in the FIGS. 1 and 3, the cassettestorage positions 24 may located at equal distances from a plane 44 ofmovement of the movable carriage 26. The plane 44 may be parallel to thefirst and the second directions. The cassette storage position 24 may beat a first side of the plane 44 and/or at a second side of the plane 44opposite the first side. The wafer transfer position 22 may bepositioned at either the first or the second side of the plane 44 atsubstantially the same distance of the plane 44 as the cassette storageposition 24.

Due to the fact that, in this embodiment, the cassette storage positions24 and the wafer transfer position 22 may be at equal distances from theplane 44, the cassette handler arms 28, 30 thus only need to have onerange of movement to be able to reach all the cassette storage positions24 and the wafer transfer position 22. This means that a simpler designfor these arms may suffice. For example, a design with three pivotpoints may suffice for the cassette handler arms 28, 30. Thus, thecassette handler arms 28, 30 and the control thereof may be relativelysimple.

In an embodiment, of which an example is shown in FIG. 2, both the firstcassette handler arm 28 and the second cassette handler arm 30 maycomprise a first and a second arm parts 46, 48 and a pivot joint 50pivotably connecting said first and second arm parts 46, 48. The firstarm part 46 may be pivotably connected to the movable carriage 26 alonga pivot joint 64. The second arm part 48 may be pivotable connected tothe cassette gripper 34 along a pivot joint 66. In this way bothcassette handler arms 28, 30 may pivot around their joints 64, 50 and 66thereby reducing or increasing the distance between end parts of therespective cassette handler arms 28, 30. Thus, a gripped wafer cassette60 may be moved towards or away from the moveable carriage 26. The wafercassette 60 may be moved away from the moveable carriage 26 topick/place said wafer cassette 60 in/from the wafer transfer position22, or on/from a cassette storage position 24. The gripper 34 with thewafer cassette 60 may be moved towards the moveable carriage 26 whentransferring of the movable carriage 26 along the first and optionallythe second direction 32, 42 is desired.

In an embodiment, the wafer cassettes 60 may be embodied as FrontOpening Unified Pods (FOUP's). FOUP's are standardized wafer cassettes60 for wafers in the industry. Using FOUP's is advantageous forexchangeability of the wafer cassettes 60 between the vertical batchfurnace assembly 10 and other wafer processing machines.

In an embodiment, of which an example is shown in FIGS. 1 and 3, thefirst cassette handler arm 28 and the second cassette handler 30 arm maybe arranged horizontally next to each other.

In an alternative embodiment, of which an example is shown in FIG. 4,the first cassette handler arm 28 and the second cassette handler arm 30may be arranged vertically above each other. It may also be possible toarrange the first cassette handler arm 28 and the second cassettehandler 30 arm neither horizontally next to each other, nor verticallyabove each other, but in an other orientation with respect to eachother, e.g. diagonally above each other. Which configuration is best fora certain vertical bath furnace assembly may depend on the configurationof the cassette handling space 12.

In an embodiment, the vertical batch furnace assembly 10 may furthercomprise at least one cassette in-out port 52 provided in a wall 16, 18bounding the cassette handling space 12. The cassette handler 26, 28, 30may be configured to additionally transfer wafer cassettes 60 to andfrom the at least one cassette in-out port 52. The at least one cassettein-out-port 52 may be provided in a second wall 18 bounding the cassettehandling space 12, opposite the first wall 16.

The at least one cassette in-out port 52 may provide the entrance to andthe exit from the vertical batch furnace assembly 10, for the exchangeof wafer cassettes 60 between the vertical batch furnace assembly 10 andthe outside world, in particular the clean room environment.

In an embodiment, the vertical batch furnace assembly 10 may comprise acassette door opener device 54 for each wafer transfer opening 20. Thecassette door opener device 54 may be configured to open a cassette doorof a wafer cassette 60 which has been placed in the wafer transferposition 22.

In an embodiment, the vertical batch furnace assembly 10 may furthercomprise a wafer handler, a process chamber, and a wafer boat handlingdevice. The wafer handler may be positioned in the wafer handling space14 and may be configured to transfer wafers between a wafer cassette 60in the wafer transfer position 22 and a wafer boat. The process chambermay be configured to process wafers accommodated in the wafer boat. Thewafer boat handling device may be positioned under the process chamberand adjacent the wafer handling space 14. The wafer boat handling devicemay be provided with the wafer boat in a wafer boat transfer position,and may be configured to transport the wafer boat between the wafer boattransfer position and the process chamber.

Although illustrative embodiments of the present invention have beendescribed above, in part with reference to the accompanying drawings, itis to be understood that the invention is not limited to theseembodiments. Variations to the disclosed embodiments can be understoodand effected by those skilled in the art in practicing the claimedinvention, from a study of the drawings, the disclosure, and theappended claims.

Reference throughout this specification to “one embodiment” or “anembodiment” means that a particular feature, structure or characteristicdescribed in connection with the embodiment is included in at least oneembodiment of the present invention. Thus, the appearances of thephrases “in one embodiment” or “in an embodiment” in various placesthroughout this description are not necessarily all referring to thesame embodiment.

Furthermore, it is noted that particular features, structures, orcharacteristics of one or more of the various embodiments which aredescribed above may be used implemented independently from one anotherand may be combined in any suitable manner to form new, not explicitlydescribed embodiments. The reference numbers used in the detaileddescription and the claims do not limit the description of theembodiments, nor do they limit the claims. The reference numbers aresolely used to clarify.

LEGEND

-   10—vertical batch furnace assembly-   12—cassette handling space-   14—wafer handling space-   16—first wall-   18—second wall-   20—wafer transfer opening-   22—wafer transfer position-   24—cassette storage position-   26—movable carriage-   28—first cassette handler arm-   30—second cassette handler arm-   32—first direction-   34—cassette gripper-   36—first guide-   38—second guide-   40—transverse guide-   42—second direction-   44—plane-   46—first arm part-   48—second arm part-   50—joint-   52—cassette in-out port-   54—cassette door opener device-   60—wafer cassette-   62—line of movement-   64—pivot joint-   66—pivot joint

1. A vertical batch furnace assembly for processing wafers comprising: acassette handling space; a wafer handling space; and a first wall andseparating the cassette handling space from the wafer handling space andhaving at least one wafer transfer opening in front of which, at a sideof the first wall which is directed to the cassette handling space, awafer transfer position for a wafer cassette is provided; wherein thecassette handling space comprises a cassette storage having a pluralityof cassette storage positions each configured to store a wafer cassetteprovided with a plurality of wafers; and a cassette handler configuredto transfer wafer cassettes between the cassette storage positions andthe wafer transfer position, wherein the cassette handler comprises: afirst cassette handler arm; and a second cassette handler arm.
 2. Thevertical batch furnace assembly according to claim 1, wherein thecassette handler further comprises a movable carriage which is movablein a first direction, wherein both the first cassette handler arm andthe second cassette handler arm are each with a respective first endconnected to the movable carriage.
 3. The vertical batch furnaceassembly according to claim 2, wherein the first cassette handler armand the second cassette handler arm each have a respective second end,wherein each respective arm is configured to move its second end awayfrom and towards its first end.
 4. The vertical batch furnace assemblyaccording claim 3, wherein both the first and second cassette handlerarms at or near the first end thereof are pivotably connected to themovable carriage of the cassette handler, and wherein the respectivecassette handler arm at or near a second end thereof comprises acassette gripper configured to grip a wafer cassette.
 5. The verticalbatch furnace assembly according to claim 4, wherein the cassettegripper of the first cassette handler arm is pivotably connected to thefirst cassette handler arm, and wherein the cassette gripper of thesecond cassette handler arm is pivotably connected to the secondcassette handler arm.
 6. The vertical batch furnace assembly accordingto claim 2, wherein the first direction is substantially vertical,wherein the cassette handler further comprises an elevator mechanismconfigured to transfer the movable carriage upwardly and downwardly sothat the first and second cassette handler arms are able to reach wafercassettes placed on cassette storage positions at different verticallevels within the cassette handling space.
 7. The vertical batch furnaceassembly according to claim 2, wherein the elevator mechanism comprisesat least one first direction guide extending in the first direction,wherein the movable carriage is moveably mounted on the at least onefirst direction guide and is moveable along the first direction.
 8. Thevertical batch furnace assembly according to claim 2, wherein themovable carriage is additionally movable in a second direction,perpendicular to the first direction.
 9. The vertical batch furnaceassembly according to claim 6, wherein the elevator mechanism comprisesat least one first direction guide extending in the first direction anda transverse guide extending in the second direction, wherein themovable carriage is moveably mounted on the transverse guide and ismoveable along the second direction, wherein the transverse guide ismovably mounted on the at least one first direction guide and ismoveable along the first direction.
 10. The vertical batch furnaceassembly according to claim 9, wherein the at least one first directionguide comprises a first guide and a second guide, wherein the transverseguide is mounted between said first guide and said second guide.
 11. Thevertical batch furnace assembly according to claim 2, wherein thecassette storage positions are located at equal distances from a line ofmovement along which the movable carriage is moveable in the firstdirection, wherein the wafer transfer position is positioned atsubstantially the same distance from the line of movement as thecassette storage positions.
 12. The vertical batch furnace assemblyaccording to claim 8, wherein the cassette storage positions are locatedat equal distances from a plane of movement of the movable carriagewhich plane is parallel to the first and the second directions, whereinthe cassette storage position are at a first side of the plane and/or ata second side of the plane opposite the first side, wherein the wafertransfer position is positioned at either the first or the second sideof the plane at substantially the same distance of the plane as thecassette storage position.
 13. The vertical batch furnace assemblyaccording to claim 1, wherein both the first cassette handler arm andthe second cassette handler arm comprise a first and a second arm partand a pivot joint pivotably connecting said first and second arm partswherein the first arm part is pivotably connected to the movablecarriage along a pivot joint, and wherein the second arm part ispivotably connected to a cassette gripper along a pivot joint.
 14. Thevertical batch furnace assembly according to claim 1, wherein the wafercassettes are embodied as Front Opening Unified Pods (FOUP's).
 15. Thevertical batch furnace assembly according to claim 1, wherein the firstcassette handler arm and the second cassette handler arm are arrangedhorizontally next to each other.
 16. The vertical batch furnace assemblyaccording to claim 1, wherein the first cassette handler arm and thesecond cassette handler arm are arranged vertically above each other.17. The vertical batch furnace assembly according to claim 1, furthercomprising at least one cassette in-out port provided in a wall boundingthe cassette handling space, wherein the cassette handler is configuredto additionally transfer wafer cassettes to and from the at least onecassette in-out port.
 18. The vertical batch furnace assembly accordingto claim 17, wherein the at least one cassette in-out-port is providedin a second wall bounding the cassette handling space, opposite thefirst wall.
 19. The vertical batch furnace assembly according to claim 1wherein for each wafer transfer opening the vertical batch furnaceassembly comprises: a cassette door opener device configured to open acassette door of a wafer cassette which has been placed in the wafertransfer position.
 20. The vertical batch furnace assembly according toclaim 1, wherein the vertical batch furnace assembly further comprises:a wafer handler positioned in the wafer handling space and configured totransfer wafers between a wafer cassette in the wafer transfer positionand a wafer boat; a process chamber configured to process wafersaccommodated in the wafer boat; and a wafer boat handling devicepositioned under the process chamber and adjacent the wafer handlingspace, wherein the wafer boat handling device is provided with the waferboat in a wafer boat transfer position, and is configured to transportthe wafer boat between the wafer boat transfer position and the processchamber.